Excess radon gas in domestic homes can be a health hazard to its occupants. Radioactive decay products from radon gas have been linked to lung cancer. It is unknown today how many homes have excess radon gas levels. A simple inexpensive method is needed to identify homes that have radon gas levels above the recommended "safe" levels. The method should determine "average" radon level, in lieu of traditional "grab sampling techniques", since home radon levels are known to fluctuate. Averaging by sampling over a long time period is not desirable, however, since an "unsafe" home environment should be identified as soon as possible.